Implementation of legend node interface for displaying preview of vector symbols and their labels and allowing interaction with the symbol / renderer. More...

#include <qgslayertreemodellegendnode.h>

Inheritance diagram for QgsSymbolLegendNode:

[legend]

Public Member Functions
	QgsSymbolLegendNode (QgsLayerTreeLayer nodeLayer, const QgsLegendSymbolItem &item, QObject parent=nullptr)
	Constructor for QgsSymbolLegendNode.
	~QgsSymbolLegendNode () override
QgsExpressionContextScope *	createSymbolScope () const
	Create an expression context scope containing symbol related variables.
QgsSymbol *	customSymbol () const
	Returns the node's custom symbol.
QVariant	data (int role) const override
	Returns data associated with the item. Must be implemented in derived class.
QSizeF	drawSymbol (const QgsLegendSettings &settings, ItemContext *ctx, double itemHeight) const override
	Draws symbol on the left side of the item.
QString	evaluateLabel (const QgsExpressionContext &context=QgsExpressionContext(), const QString &label=QString())
	Evaluates and returns the text label of the current node.
QJsonObject	exportSymbolToJson (const QgsLegendSettings &settings, const QgsRenderContext &context) const override
	Adds a symbol in base64 string within a JSON object with the key "icon".
Qt::ItemFlags	flags () const override
	Returns item flags associated with the item. Default implementation returns Qt::ItemIsEnabled.
QSize	iconSize () const
void	invalidateMapBasedData () override
	Notification from model that information from associated map view has changed.
bool	isScaleOK (double scale) const override
QSize	minimumIconSize () const
	Calculates the minimum icon size to prevent cropping.
QSize	minimumIconSize (QgsRenderContext *context) const
	Calculates the minimum icon size to prevent cropping.
QgsLegendPatchShape	patchShape () const
	Returns the symbol patch shape to use when rendering the legend node symbol.
void	setCustomSymbol (QgsSymbol *symbol)
	Sets the node's custom symbol.
bool	setData (const QVariant &value, int role) override
	Sets some data associated with the item. Default implementation does nothing and returns `false`.
void	setEmbeddedInParent (bool embedded) override
void	setIconSize (QSize sz)
	Set the icon size.
void	setPatchShape (const QgsLegendPatchShape &shape)
	Sets the symbol patch shape to use when rendering the legend node symbol.
void	setSymbol (QgsSymbol *symbol)
	Sets the symbol to be used by the legend node.
void	setTextOnSymbolLabel (const QString &label)
	Sets label of text to be shown on top of the symbol.
void	setTextOnSymbolTextFormat (const QgsTextFormat &format)
	Sets format of text to be shown on top of the symbol.
void	setUserLabel (const QString &userLabel) override
const QgsSymbol *	symbol () const
	Returns the symbol used by the legend node.
QString	symbolLabel () const
	Label of the symbol, user defined label will be used, otherwise will default to the label made by QGIS.
QString	textOnSymbolLabel () const
	Returns label of text to be shown on top of the symbol.
QgsTextFormat	textOnSymbolTextFormat () const
	Returns text format of the label to be shown on top of the symbol.
Public Member Functions inherited from QgsLayerTreeModelLegendNode
virtual bool	columnBreak () const
	Returns whether a forced column break should occur before the node.
virtual ItemMetrics	draw (const QgsLegendSettings &settings, ItemContext &ctx)
	Entry point called from QgsLegendRenderer to do the rendering.
virtual QSizeF	drawSymbolText (const QgsLegendSettings &settings, ItemContext *ctx, QSizeF symbolSize) const
	Draws label on the right side of the item.
QJsonObject	exportToJson (const QgsLegendSettings &settings, const QgsRenderContext &context)
	Entry point called from QgsLegendRenderer to do the rendering in a JSON object.
virtual bool	isEmbeddedInParent () const
QgsLayerTreeLayer *	layerNode () const
	Returns pointer to the parent layer node.
QgsLayerTreeModel *	model () const
	Returns pointer to model owning this legend node.
virtual void	setColumnBreak (bool breakBeforeNode)
	Sets whether a forced column break should occur before the node.
virtual void	setUserPatchSize (QSizeF size)
	Sets the user (overridden) size for the legend node.
virtual QString	userLabel () const
virtual QSizeF	userPatchSize () const
	Returns the user (overridden) size for the legend node.

Static Public Attributes
static double	MAXIMUM_SIZE = -1.0
static double	MINIMUM_SIZE = -1.0
static const QgsSettingsEntryDouble *	settingsLegendSymbolMaximumSize = new QgsSettingsEntryDouble( u"symbol-maximum-size"_s, QgsSettingsTree::sTreeLayerTree, 20.0, u"Maximum size (in millimeters) at which symbols are rendered in the layer tree legend. Symbols larger than this size are scaled down to fit."_s )
static const QgsSettingsEntryDouble *	settingsLegendSymbolMinimumSize = new QgsSettingsEntryDouble( u"symbol-minimum-size"_s, QgsSettingsTree::sTreeLayerTree, 0.5, u"Minimum size (in millimeters) at which symbols are rendered in the layer tree legend. Symbols smaller than this size are scaled up for readability."_s )

Additional Inherited Members
Public Types inherited from QgsLayerTreeModelLegendNode
enum class	CustomRole : int { RuleKey = Qt::UserRole , ParentRuleKey , NodeType , IsDataDefinedSize }
	Legend node data roles. More...
enum	NodeTypes { SimpleLegend , SymbolLegend , RasterSymbolLegend , ImageLegend , WmsLegend , DataDefinedSizeLegend , EmbeddedWidget , ColorRampLegend }
	Types of legend nodes. More...
Public Slots inherited from QgsLayerTreeModelLegendNode
void	checkAllItems ()
	Checks all checkable items belonging to the same layer as this node.
void	toggleAllItems ()
	Toggle all checkable items belonging to the same layer as this node.
void	uncheckAllItems ()
	Unchecks all checkable items belonging to the same layer as this node.
Signals inherited from QgsLayerTreeModelLegendNode
void	dataChanged ()
	Emitted on internal data change so the layer tree model can forward the signal to views.
void	sizeChanged ()
	Emitted when the size of this node changes.
Protected Member Functions inherited from QgsLayerTreeModelLegendNode
	QgsLayerTreeModelLegendNode (QgsLayerTreeLayer nodeL, QObject parent=nullptr)
	Construct the node with pointer to its parent layer node.
QgsRenderContext *	createTemporaryRenderContext () const
	Returns a temporary context or `nullptr` if legendMapViewData are not valid.
Protected Attributes inherited from QgsLayerTreeModelLegendNode
bool	mColumnBreakBeforeNode = false
bool	mEmbeddedInParent = false
QgsLayerTreeLayer *	mLayerNode = nullptr
QgsLegendPatchShape	mPatchShape
QString	mUserLabel
QSizeF	mUserSize

Detailed Description

Implementation of legend node interface for displaying preview of vector symbols and their labels and allowing interaction with the symbol / renderer.

Definition at line 404 of file qgslayertreemodellegendnode.h.

Constructor & Destructor Documentation

◆ QgsSymbolLegendNode()

QgsSymbolLegendNode::QgsSymbolLegendNode	(	QgsLayerTreeLayer *	nodeLayer,
		const QgsLegendSymbolItem &	item,
		QObject *	parent = nullptr )

Constructor for QgsSymbolLegendNode.

Parameters

nodeLayer	layer node
item	the legend symbol item
parent	attach a parent QObject to the legend node.

Definition at line 348 of file qgslayertreemodellegendnode.cpp.

◆ ~QgsSymbolLegendNode()

QgsSymbolLegendNode::~QgsSymbolLegendNode ( )

overridedefault

Member Function Documentation

◆ createSymbolScope()

QgsExpressionContextScope * QgsSymbolLegendNode::createSymbolScope ( ) const

Create an expression context scope containing symbol related variables.

The caller takes ownership of the returned object.

Since: QGIS 3.36

Definition at line 995 of file qgslayertreemodellegendnode.cpp.

◆ customSymbol()

QgsSymbol * QgsSymbolLegendNode::customSymbol ( ) const

Returns the node's custom symbol.

If a non-nullptr value is returned, then this symbol will be used for rendering the legend node instead of the default symbol().

See also: setCustomSymbol()

Since: QGIS 3.14

Definition at line 474 of file qgslayertreemodellegendnode.cpp.

◆ data()

QVariant QgsSymbolLegendNode::data ( int role ) const

overridevirtual

Returns data associated with the item. Must be implemented in derived class.

Implements QgsLayerTreeModelLegendNode.

Definition at line 569 of file qgslayertreemodellegendnode.cpp.

◆ drawSymbol()

QSizeF QgsSymbolLegendNode::drawSymbol	(	const QgsLegendSettings &	settings,
		ItemContext *	ctx,
		double	itemHeight ) const

overridevirtual

Draws symbol on the left side of the item.

Parameters

settings	Legend layout configuration
ctx	Context for rendering - may be `nullptr` if only doing layout without actual rendering
itemHeight	Minimal height of the legend item - used for correct positioning when rendering

Returns: Real size of the symbol (may be bigger than "normal" symbol size from settings)

Reimplemented from QgsLayerTreeModelLegendNode.

Definition at line 671 of file qgslayertreemodellegendnode.cpp.

◆ evaluateLabel()

QString QgsSymbolLegendNode::evaluateLabel	(	const QgsExpressionContext &	context = QgsExpressionContext(),
		const QString &	label = QString() )

Evaluates and returns the text label of the current node.

Parameters

context	extra QgsExpressionContext to use for evaluating the expression
label	text to evaluate instead of the layer layertree string

Since: QGIS 3.10

Definition at line 959 of file qgslayertreemodellegendnode.cpp.

◆ exportSymbolToJson()

QJsonObject QgsSymbolLegendNode::exportSymbolToJson	(	const QgsLegendSettings &	settings,
		const QgsRenderContext &	context ) const

overridevirtual

Adds a symbol in base64 string within a JSON object with the key "icon".

Parameters

settings	Legend layout configuration
context	Rendering context

Since: QGIS 3.8

Reimplemented from QgsLayerTreeModelLegendNode.

Definition at line 848 of file qgslayertreemodellegendnode.cpp.

◆ flags()

Qt::ItemFlags QgsSymbolLegendNode::flags ( ) const

overridevirtual

Returns item flags associated with the item. Default implementation returns Qt::ItemIsEnabled.

Reimplemented from QgsLayerTreeModelLegendNode.

Definition at line 377 of file qgslayertreemodellegendnode.cpp.

◆ iconSize()

QSize QgsSymbolLegendNode::iconSize ( ) const

inline

Definition at line 450 of file qgslayertreemodellegendnode.h.

◆ invalidateMapBasedData()

void QgsSymbolLegendNode::invalidateMapBasedData ( )

overridevirtual

Notification from model that information from associated map view has changed.

Default implementation does nothing.

Reimplemented from QgsLayerTreeModelLegendNode.

Definition at line 916 of file qgslayertreemodellegendnode.cpp.

◆ isScaleOK()

bool QgsSymbolLegendNode::isScaleOK ( double scale ) const

inlineoverridevirtual

Reimplemented from QgsLayerTreeModelLegendNode.

Definition at line 442 of file qgslayertreemodellegendnode.h.

◆ minimumIconSize() [1/2]

QSize QgsSymbolLegendNode::minimumIconSize ( ) const

Calculates the minimum icon size to prevent cropping.

When evaluating the size for multiple icons it is more efficient to create a single render context in advance and use the variant which accepts a QgsRenderContext argument.

Definition at line 386 of file qgslayertreemodellegendnode.cpp.

◆ minimumIconSize() [2/2]

QSize QgsSymbolLegendNode::minimumIconSize ( QgsRenderContext * context ) const

Calculates the minimum icon size to prevent cropping.

When evaluating the size for multiple icons it is more efficient to create a single render context in advance and call this method instead of minimumIconSize().

Definition at line 392 of file qgslayertreemodellegendnode.cpp.

◆ patchShape()

QgsLegendPatchShape QgsSymbolLegendNode::patchShape ( ) const

Returns the symbol patch shape to use when rendering the legend node symbol.

See also: setPatchShape()

Since: QGIS 3.14

Definition at line 457 of file qgslayertreemodellegendnode.cpp.

◆ setCustomSymbol()

void QgsSymbolLegendNode::setCustomSymbol ( QgsSymbol * symbol )

Sets the node's custom symbol.

If a non-nullptr value is set, then this symbol will be used for rendering the legend node instead of the default symbol().

Ownership of symbol is transferred.

See also: customSymbol()

Since: QGIS 3.14

Definition at line 479 of file qgslayertreemodellegendnode.cpp.

◆ setData()

bool QgsSymbolLegendNode::setData	(	const QVariant &	value,
		int	role )

overridevirtual

Sets some data associated with the item. Default implementation does nothing and returns false.

Reimplemented from QgsLayerTreeModelLegendNode.

Definition at line 646 of file qgslayertreemodellegendnode.cpp.

◆ setEmbeddedInParent()

void QgsSymbolLegendNode::setEmbeddedInParent ( bool embedded )

overridevirtual

Reimplemented from QgsLayerTreeModelLegendNode.

Definition at line 909 of file qgslayertreemodellegendnode.cpp.

◆ setIconSize()

void QgsSymbolLegendNode::setIconSize ( QSize sz )

Set the icon size.

Definition at line 925 of file qgslayertreemodellegendnode.cpp.

◆ setPatchShape()

void QgsSymbolLegendNode::setPatchShape ( const QgsLegendPatchShape & shape )

Sets the symbol patch shape to use when rendering the legend node symbol.

See also: patchShape()

Since: QGIS 3.14

Definition at line 469 of file qgslayertreemodellegendnode.cpp.

◆ setSymbol()

void QgsSymbolLegendNode::setSymbol ( QgsSymbol * symbol )

Sets the symbol to be used by the legend node.

The symbol change is also propagated to the associated vector layer's renderer.

Parameters

symbol new symbol for node. Ownership is transferred.

See also: symbol()

Definition at line 484 of file qgslayertreemodellegendnode.cpp.

◆ setTextOnSymbolLabel()

void QgsSymbolLegendNode::setTextOnSymbolLabel ( const QString & label )

inline

Sets label of text to be shown on top of the symbol.

Since: QGIS 3.2

Definition at line 491 of file qgslayertreemodellegendnode.h.

◆ setTextOnSymbolTextFormat()

void QgsSymbolLegendNode::setTextOnSymbolTextFormat ( const QgsTextFormat & format )

inline

Sets format of text to be shown on top of the symbol.

Since: QGIS 3.2

Definition at line 503 of file qgslayertreemodellegendnode.h.

◆ setUserLabel()

void QgsSymbolLegendNode::setUserLabel ( const QString & userLabel )

inlineoverridevirtual

Reimplemented from QgsLayerTreeModelLegendNode.

Definition at line 436 of file qgslayertreemodellegendnode.h.

◆ symbol()

const QgsSymbol * QgsSymbolLegendNode::symbol ( ) const

Returns the symbol used by the legend node.

See also: setSymbol()

Definition at line 438 of file qgslayertreemodellegendnode.cpp.

◆ symbolLabel()

QString QgsSymbolLegendNode::symbolLabel ( ) const

Label of the symbol, user defined label will be used, otherwise will default to the label made by QGIS.

Since: QGIS 3.10

Definition at line 443 of file qgslayertreemodellegendnode.cpp.

◆ textOnSymbolLabel()

QString QgsSymbolLegendNode::textOnSymbolLabel ( ) const

inline

Returns label of text to be shown on top of the symbol.

Since: QGIS 3.2

Definition at line 485 of file qgslayertreemodellegendnode.h.

◆ textOnSymbolTextFormat()

QgsTextFormat QgsSymbolLegendNode::textOnSymbolTextFormat ( ) const

inline

Returns text format of the label to be shown on top of the symbol.

Since: QGIS 3.2

Definition at line 497 of file qgslayertreemodellegendnode.h.

Member Data Documentation

◆ MAXIMUM_SIZE

double QgsSymbolLegendNode::MAXIMUM_SIZE = -1.0

static

Definition at line 410 of file qgslayertreemodellegendnode.h.

◆ MINIMUM_SIZE

double QgsSymbolLegendNode::MINIMUM_SIZE = -1.0

static

Definition at line 409 of file qgslayertreemodellegendnode.h.

◆ settingsLegendSymbolMaximumSize

const QgsSettingsEntryDouble * QgsSymbolLegendNode::settingsLegendSymbolMaximumSize = new QgsSettingsEntryDouble( u"symbol-maximum-size"_s, QgsSettingsTree::sTreeLayerTree, 20.0, u"Maximum size (in millimeters) at which symbols are rendered in the layer tree legend. Symbols larger than this size are scaled down to fit."_s )

static

Definition at line 414 of file qgslayertreemodellegendnode.h.

◆ settingsLegendSymbolMinimumSize

const QgsSettingsEntryDouble * QgsSymbolLegendNode::settingsLegendSymbolMinimumSize = new QgsSettingsEntryDouble( u"symbol-minimum-size"_s, QgsSettingsTree::sTreeLayerTree, 0.5, u"Minimum size (in millimeters) at which symbols are rendered in the layer tree legend. Symbols smaller than this size are scaled up for readability."_s )

static

Definition at line 413 of file qgslayertreemodellegendnode.h.

The documentation for this class was generated from the following files:

/build/qgis-4.1.0+git20260503+376402f9aeb+99sid/src/core/layertree/qgslayertreemodellegendnode.h
/build/qgis-4.1.0+git20260503+376402f9aeb+99sid/src/core/layertree/qgslayertreemodellegendnode.cpp

Public Member Functions

Static Public Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QgsSymbolLegendNode()

◆ ~QgsSymbolLegendNode()

Member Function Documentation

◆ createSymbolScope()

◆ customSymbol()

◆ data()

◆ drawSymbol()

◆ evaluateLabel()

◆ exportSymbolToJson()

◆ flags()

◆ iconSize()

◆ invalidateMapBasedData()

◆ isScaleOK()

◆ minimumIconSize() [1/2]

◆ minimumIconSize() [2/2]

◆ patchShape()

◆ setCustomSymbol()

◆ setData()

◆ setEmbeddedInParent()

◆ setIconSize()

◆ setPatchShape()

◆ setSymbol()

◆ setTextOnSymbolLabel()

◆ setTextOnSymbolTextFormat()

◆ setUserLabel()

◆ symbol()

◆ symbolLabel()

◆ textOnSymbolLabel()

◆ textOnSymbolTextFormat()

Member Data Documentation

◆ MAXIMUM_SIZE

◆ MINIMUM_SIZE

◆ settingsLegendSymbolMaximumSize

◆ settingsLegendSymbolMinimumSize